Attacking decks tend to be packing ways to grant haste with protection in the form of Lightning Greaves or Swiftfoot Boots
Creatures with wither deal damage to players normally
Just making two tokens means youll put two +1/+1 counters on every creature you control, and that gets way more powerful with cards like Doubling Season, Anointed Procession, or +1/+1 counter commanders
While that's not the most terrible idea, the likelihood in a Niv-Mizzet deck is that the other spell you're casting is a burn spell that could do the same, and I have to feel that you're going to be better off casting it by itself, rather than putting all your eggs in one basket
Set: Ascended Heroes Increase: +$590.43 Current Market Price: $1,176.51 Everyone knew Mega Gengar ex would overtake Mega Dragonite ex as the most valuable card in Ascended Heroes
Thats just a part of the games normal back-and-forth